Suppress warnings on dead inherent methods when allowing dead types

Code

#[allow(dead_code)]
struct Foo;

impl Foo {
    fn foo(&self) {}
}

Current output

warning: method `foo` is never used
 --> src/lib.rs:5:8
  |
4 | impl Foo {
  | -------- method in this implementation
5 |     fn foo(&self) {}
  |        ^^^
  |
  = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default

Desired output

No warning

Rationale and extra context

Allowing on the impl block can suppress warning both on methods and types.

struct Foo;

#[allow(dead_code)]
impl Foo {
    fn foo(&self) {}
}

But I think it's more intuitive to just allow on types.

Futhermore, considering that when we have dead types, no methods could be used. So maybe we can also suppress warnings for items in the impl block when there has been warnings for the type. 🤔

Other cases

Rust Version

Build using the Nightly version: 1.93.0-nightly

(2025-11-19 07bdbaedc63094281483)

Anything else?

No response

Start by compiling the minimal Rust reproduction with the reported Nightly version and compare the current diagnostic with the desired no-warning output. Investigate how dead-code warnings are emitted for methods in an impl of a type marked #[allow(dead_code)]; done means the shown case produces no warning.